The Food and Drug Administration on Monday released documents in which its career scientists say the evidence supporting seven unapproved peptide injections is insufficient to warrant removing them from a restricted category, directly challenging Health Secretary Robert F. Kennedy Jr.’s push to expand access.

The compounds under review include BPC-157, TB-500, and MOTs-C, peptides that have gained popularity among wellness influencers and some clinicians for uses including injury recovery, muscle repair, and metabolism enhancement. They are typically taken as subcutaneous injections.

The FDA staff review flags concerns about a consistent lack of safety and efficacy data. “We just don’t have enough data to support their use,” Dr. Alexander Weber, an orthopedic surgeon and chief of sports medicine at the University of Southern California, told NPR. Weber has published a review of the peptide evidence.

The Biden administration in 2023 moved nearly 20 peptides into a category that essentially prohibits compounding pharmacies from manufacturing them. Since then, users have sourced the products through a gray market, often from overseas suppliers.

Kennedy, who oversees the FDA through the Department of Health and Human Services, has said he is a “big fan” of peptides and has used some himself. He has characterized the 2023 restrictions as “illegal” and advocated for allowing compounding pharmacies to again offer the drugs.

The advisory committee that will review the evidence on July 23–24 is composed of members with ties to the peptide industry, including some who work for companies that market injectable peptides. Previous FDA panels on the topic were made up of academics and researchers.

The committee will consider specific indications for the peptides, including ulcerative colitis, wound healing, obesity, and migraines. It will make recommendations; the FDA is not bound to follow them but typically does. The panel is scheduled to reconvene in February to review additional peptides.

MSI previously reported on the FDA’s April announcement that it would convene the advisory panel, and on the rapid growth of the peptide market as businesses prepared for the regulatory shift.